Novel In Vivo Imaging Analysis of an Inner Ear Drug Delivery System in Mice: Comparison of Inner Ear Drug Concentrations over Time after Transtympanic and Systemic Injections

Objective

Systemic steroid injections are used to treat idiopathic sudden-onset sensorineural hearing loss (ISSHL) and some inner ear disorders. Recent studies show that transtympanic (TT) steroid injections are effective for treating ISSHL. As in vivo monitoring of drug delivery dynamics for inner ear is lacking, its time course and dispersion of drugs is unknown. Here, we used a new in vivo imaging system to monitor drug delivery in live mice and to compare drug concentrations over time after TT and systemic injections.

Methods

Luciferin delivered into the inner ears of GFAP-Luc transgenic mice reacted with luciferase in GFAP-expressing cells in the cochlear spiral ganglion, resulting in photon bioluminescence. We used the Xenogen IVIS® imaging system to measure how long photons continued to be emitted in the inner ear after TT or systemic injections of luciferin, and then compared the associated drug dynamics.

Results

The response to TT and IP injections differed significantly. Photons were detected five minutes after TT injection, peaking at ∼20 minutes. By contrast, photons were first detected 30 minutes after i.p. injection. TT and i.p. drug delivery time differed considerably. With TT injections, photons were detected earlier than with IP injections. Photon bioluminescence also disappeared sooner. Delivery time varied with TT injections.

Conclusions

We speculate that the drug might enter the Eustachian tube from the middle ear. We conclude that inner-ear drug concentration can be maintained longer if the two injection routes are combined. As the size of luciferin differs from that of therapeutics like dexamethasone, combining drugs with luciferin may advance our understanding of in vivo drug delivery dynamics in the inner ear.     

Expression of Cyclin D1 Is Associated with ��-Catenin Expression and Correlates with Good Prognosis in Colorectal Adenocarcinoma

Background

The aim of this study is to investigate the prevalence and prognostic impact of β-catenin and cyclin D1 expression in colorectal carcinoma (CRC) patients.

Method

We evaluated immunohistochemial expression of β-catenin and cyclin D1 using 2-mm cores from 220 CRC patients for tissue microarray, and its significance was statistically evaluated.

Result

Positive expression of β-catenin and cyclin D1 was found in 72.5% (158 of 218 cases) and 59.4% (129 of 217 cases) of CRC patients, respectively. Expression of β-catenin was significantly correlated with tumor location (P = .017), differentiation (P = .010), lymph node metastasis (P = .032), preoperative carcinoembryonic antigen level (P = .032), and cyclin D1 expression (P = .005). Expression of cyclin D1 was significantly correlated with recurrence and/or metastasis (P = .004). In univariate analysis, β-catenin expression predicted more favorable overall survival (P = .022) and cyclin D1 expression predicted both more favorable overall survival and relapse-free survival (P = .004 and P = .006, respectively). Multivariate analysis showed that tumor stage and expression of cyclin D1 were independent prognostic factors significantly associated with overall survival and relapse-free survival.

Conclusion

This study shows that expression of β-catenin and cyclin D1 is associated with favorable clinicopathologic variables and it is a clinically significant prognostic indicator for CRC patients.     

The Green Monster Process for the Generation of Yeast Strains Carrying Multiple Gene Deletions

Phenotypes for a gene deletion are often revealed only when the mutation is tested in a particular genetic background or environmental condition^1,2. There are examples where many genes need to be deleted to unmask hidden gene functions^3,4. Despite the potential for important discoveries, genetic interactions involving three or more genes are largely unexplored. Exhaustive searches of multi-mutant interactions would be impractical due to the sheer number of possible combinations of deletions. However, studies of selected sets of genes, such as sets of paralogs with a greater a priori chance of sharing a common function, would be informative.In the yeast Saccharomyces cerevisiae, gene knockout is accomplished by replacing a gene with a selectable marker via homologous recombination. Because the number of markers is limited, methods have been developed for removing and reusing the same marker^5,6,7,8,9,10. However, sequentially engineering multiple mutations using these methods is time-consuming because the time required scales linearly with the number of deletions to be generated.Here we describe the Green Monster method for routinely engineering multiple deletions in yeast¹¹. In this method, a green fluorescent protein (GFP) reporter integrated into deletions is used to quantitatively label strains according to the number of deletions contained in each strain (Figure 1). Repeated rounds of assortment of GFP-marked deletions via yeast mating and meiosis coupled with flow-cytometric enrichment of strains carrying more of these deletions lead to the accumulation of deletions in strains (Figure 2). Performing multiple processes in parallel, with each process incorporating one or more deletions per round, reduces the time required for strain construction.The first step is to prepare haploid single-mutants termed ''ProMonsters,'' each of which carries a GFP reporter in a deleted locus and one of the ''toolkit'' loci—either Green Monster GMToolkit-a or GMToolkit-α at the can1Δ locus (Figure 3). Using strains from the yeast deletion collection¹², GFP-marked deletions can be conveniently generated by replacing the common KanMX4 cassette existing in these strains with a universal GFP-URA3 fragment. Each GMToolkit contains: either the a- or α-mating-type-specific haploid selection marker¹ and exactly one of the two markers that, when both GMToolkits are present, collectively allow for selection of diploids.The second step is to carry out the sexual cycling through which deletion loci can be combined within a single cell by the random assortment and/or meiotic recombination that accompanies each cycle of mating and sporulation.     

Microbe-specific C3b deposition in the horseshoe crab complement system in a C2/factor B-dependent or -independent manner

Complement C3 plays an essential role in the opsonization of pathogens in the mammalian complement system, whereas the molecular mechanism underlying C3 activation in invertebrates remains unknown. To understand the molecular mechanism of C3b deposition on microbes, we characterized two types of C2/factor B homologs (designated TtC2/Bf-1 and TtC2/Bf-2) identified from the horseshoe crab Tachypleus tridentatus. Although the domain architectures of TtC2/Bf-1 and TtC2/Bf-2 were identical to those of mammalian homologs, they contained five-repeated and seven-repeated complement control protein domains at their N-terminal regions, respectively. TtC2/Bf-1 and TtC2/Bf-2 were synthesized and glycosylated in hemocytes and secreted to hemolymph plasma, which existed in a complex with C3 (TtC3), and their activation by microbes was absolutely Mg(2+)-dependent. Flow cytometric analysis revealed that TtC3b deposition was Mg(2+)-dependent on Gram-positive bacteria or fungi, but not on Gram-negative bacteria. Moreover, this analysis demonstrated that Ca(2+)-dependent lectins (C-reactive protein-1 and tachylectin-5A) were required for TtC3b deposition on Gram-positive bacteria, and that a Ca(2+)-independent lectin (Tachypleus plasma lectin-1) was definitely indispensable for TtC3b deposition on fungi. In contrast, a horseshoe crab lipopolysaccharide-sensitive protease factor C was necessary and sufficient to deposit TtC3b on Gram-negative bacteria. We conclude that plasma lectins and factor C play key roles in microbe-specific TtC3b deposition in a C2/factor B-dependent or -independent manner.     

MCP1 SNPs and pulmonary tuberculosis in cohorts from West Africa, the USA and Argentina: lack of association or epistasis with IL12B polymorphisms

The monocyte chemotactic protein-1 (MCP-1) is a chemokine that plays an important role in the recruitment of monocytes to M. tuberculosis infection sites, and previous studies have reported that genetic variants in MCP1 are associated with differential susceptibility to pulmonary tuberculosis (PTB). We examined eight MCP1 single nucleotide polymorphisms (SNPs) in a multi-ethnic, case-control design that included: 321 cases and 346 controls from Guinea-Bissau, 258 cases and 271 controls from The Gambia, 295 cases and 179 controls from the U.S. (African-Americans), and an additional set of 237 cases and 144 controls of European ancestry from the U.S. and Argentina. Two locus interactions were also examined for polymorphisms in MCP1 and interleukin 12B (IL12B), another gene implicated in PTB risk. Examination of previously associated MCP1 SNPs rs1024611 (-2581A/G), rs2857656 (-362G/C) and rs4586 (+900C/T) did not show evidence for association. One interaction between rs2857656 and IL12B SNP rs2288831 was observed among Africans but the effect was in the opposite direction in Guineans (OR = 1.90, p = 0.001) and Gambians (OR = 0.64, p = 0.024). Our data indicate that the effect of genetic variation within MCP1 is not clear cut and additional studies will be needed to elucidate its role in TB susceptibility.     

d-Xylose Isomerase from a Marine Bacterium, Vibrio sp. Strain XY-214, and d-Xylulose Production from β-1,3-Xylan

The xylA gene from a marine bacterium, Vibrio sp. strain XY-214, encoding d-xylose isomerase (XylA) was cloned and expressed in Escherichia coli. The xylA gene consisted of 1,320-bp nucleotides encoding a protein of 439 amino acids with a predicted molecular weight of 49,264. XylA was classified into group II xylose isomerases. The native XylA was estimated to be a homotetramer with a molecular mass of 190 kDa. The purified recombinant XylA exhibited maximal activity at 60°C and pH 7.5. Its apparent K _m values for d-xylose and d-glucose were 7.93 and 187 mM, respectively. Furthermore, we carried out d-xylulose production from β-1,3-xylan, a major cell wall polysaccharide component of the killer alga Caulerpa taxifolia. The synergistic action of β-1,3-xylanase (TxyA) and β-1,3-xylosidase (XloA) from Vibrio sp. strain XY-214 enabled efficient saccharification of β-1,3-xylan to d-xylose. d-Xylose was then converted to d-xylulose by using XylA from the strain XY-214. The conversion rate of d-xylose to d-xylulose by XylA was found to be approximately 40% in the presence of 4 mM sodium tetraborate after 2 h of incubation. These results demonstrated that TxyA, XloA, and XylA from Vibrio sp. strain XY-214 are useful tools for d-xylulose production from β-1,3-xylan. Because d-xylulose can be used as a source for ethanol fermentation by yeast Saccharomyces cerevisiae, the present study will provide a basis for ethanol production from β-1,3-xylan.     

Input, retention, and invertebrate colonization of allochthonous litter in streams bordered by deciduous broadleaved forest, a conifer plantation, and a clear-cut site in southwestern Japan

In headwater streams, conifer plantation forestry may affect stream communities through the quantity and quality of basal resources (allochthonous litter). We compared (1) the seasonal patterns of litter input from the riparian canopy, (2) those for the abundance of benthic and drifting litter in streams, and (3) the density of litter-associated invertebrates among streams bordered by deciduous broadleaved forest, a plantation of Japanese cedar (Cryptomeria japonica), and a clear-cut site, to extract the characteristics of conifer-plantation streams in terms of litter dynamics and benthic invertebrates. The results illustrate differences in litter input and in-stream processes between the broadleaved and plantation sites, although the total annual inputs from canopy were similar. In the broadleaved site, high litter storage was limited to winter, probably because pulsed inputs of litter in autumn were retained on the streambed but rapidly processed. In contrast, litter input was more constant at the plantation site, and litter was stored throughout the year. Although the litter-patch-specific density of total invertebrates was similar between the broadleaved and plantation sites, estimates of the reach-scale, habitat-weighted density considering differences in the coverage area of litter patches revealed considerable differences. Although the habitat-weighted density of total invertebrates was lower at the plantation site than at the broadleaved site in winter, it was noticeably higher at the plantation site in summer, owing to the seasonal stability of benthic litter abundance. Our results emphasized the importance of considering the spatiotemporal availability of benthic litter when assessing the effects of conifer plantations on stream ecosystems.     

TRIM45 negatively regulates NF-κB-mediated transcription and suppresses cell proliferation

The signaling adapter protein CRK is an indispensable molecule involved in regulating the malignant potential of human cancers. CRK-like (CRKL) is a hematopoietic cell-dominant homologue of CRK that is reported to be phosphorylated by BCR-ABL tyrosine kinase in chronic myelogenous leukemia patients, but its biological function in non-hematopoietic tumors remains unclear. In this study, we explored the tumorigenic role of CRKL in head and neck squamous cell carcinoma (HNSCC) in vitro and in vivo. Immunoprecipitation analysis of HNSCC cell line, HSC-3 cells, showed that the dominant binding partner for C3G was CRKL, not CRK. To clarify the molecular function of CRKL, we established lentiviral shRNA-mediated CRKL-knockdown HNSCC cell lines. In CRKL-knockdown HSC-3 and HSC-4 cells, cell growth and motility were diminished compared to control cells. Cell adhesion assays showed that cell attachment onto both fibronectin- and collagen-coated dishes was significantly suppressed in CRKL-knockdown HSC-3 cells, while no significant change was observed for poly-l-lysine-coated dishes. Immunofluorescence staining revealed that focal adhesion was reduced in CRKL-knockdown HSC-3 cells. With a pulldown assay, CRKL-knockdown HSC-3 cells showed decreased amounts of active Rap1 compared to control cells. Moreover, in an in vivo assay, tumor formation of CRKL-knockdown HSC-3 cells in nude mice was significantly abrogated. Our results indicate that CRKL regulates HNSCC-cell growth, motility, and integrin-dependent cell adhesion, suggesting that CRKL plays a principal role in HNSCC tumorigenicity.